Montreal’s public health agency warned residents on Thursday to be vigilant as warmer temperatures drive people outdoors, after 161 lyme disease cases were recorded in 2025. The total was the highest number recorded since data collection began in 2003. The warning comes as summer tick exposure increases.
Montreal Public Health
The agency linked its warning to the rise in cases and the season’s outdoor activity. Lyme disease is the most common tick-borne illness, and it is primarily transmitted through the bite of an infected blacklegged tick or deer tick.
Residents can lower their risk by avoiding tick habitat where possible and checking for ticks after time outside. Ticks thrive in wooded areas, forests, tall grasses and leaf litter, and they should be removed within 48 hours to prevent disease.
Nicholas Ogden
Nicholas Ogden, a research scientist and director of the modelling hub division at the Public Health Agency of Canada, said ticks go through a two-year life cycle and can become vectors of the bacteria after feeding on infected birds or rodents. He said humans often contract Lyme disease after being bitten by tiny ticks in the nymph stage.
Ogden also noted that there are more than 40 different types of ticks in Canada, with two types carrying Borrelia burgdorferi, the bacteria that cause Lyme disease in humans. The blacklegged or deer tick is found in Southern and Eastern Canada, while the western blacklegged tick is found in the West.
Lyme Disease Cases
Lyme disease can be cured with antibiotics if caught early, but it can cause long-term issues, including joint pain and cognitive problems if left untreated. For Montreal residents heading outdoors this season, the practical step is simple: avoid tick habitat when possible, check skin and clothing after being outside, and remove any tick quickly.
